Tiny white brittle stars

[chsreef]

Over the past couple days, I've noticed hundreds of tiny white brittle stars in my tank. Where do these come from? I have one fairly large brown/black brittle star in the tank. Are these anyway harmful? tks

 

[fender]

hitchhikers on rock. They are not harmful. Very good to have. There are sites where people pay to get these in their tanks in detrivore kits.

 

[fish sense]

I had a bunch in my tank as HH. But my fish slowly got to them. Never harmed anything.